ABSTRACT
Evaluation of metal levels in commercial organic amendments in Chile: Compliance with national standards

Vicente Beltrán1, Winfred Espejo1*, José Celis2, Christian Guajardo1, and Marco Sandoval1
 
Commercial amendments can introduce hazardous chemical constituents into the soil profile, resulting in the long-term accumulation of heavy metals within the edaphic matrix. Fluctuations in key physicochemical parameters can trigger metal remobilization, thereby increasing their bioavailability within the terrestrial food chain and posing a severe risk to human health. We evaluated the concentrations of Cd, Cu, Cr, Ni, Pb, and Zn in ten commercial organic amendments from the local market in Chillán, Chile, benchmarking them against the national standard NCh 2880. Following physicochemical characterization, the burden of metals was quantified using inductively coupled plasma optical emission spectroscopy (ICP-OES). The results revealed significant variation (p < 0.05) in metal content, reflecting the diverse origins of the studied amendments. While Cd, Cr, Ni, and Pb showed moderate fluctuations, Cu and Zn reached concentrations as high as 197.84 and 214.07 mg kg-1, respectively. Such pronounced heterogeneity underscores the importance of tailored site assessments to prevent excessive metal loading. Furthermore, uncontrolled production processes resulted in critical pH and salinity levels which, combined with the presence of metals, suggest that phytotoxicity from these factors could pose a serious health menace to soil and human. Significant inter-brand variations emphasize that quality is directly contingent upon manufacturing processes and raw material selection. These results confirm that despite general regulatory compliance, the inherent heterogeneity of these amendments requires individual monitoring to prevent long-term metal accumulation in agricultural soils.
Key words: Biofertilizers, compost, organic waste, soil contamination, soil remediation.
1Universidad de Concepción, Facultad de Agronomía, Chillán, Chile.
2Universidad de Concepción, Facultad de Ciencias Veterinarias, Chillán, Chile.
*Corresponding author (winfredespejo@udec.cl).
Received: 25 June 2026; Accepted: 10 September 2026, Available online: 29 October 2026.